Dental chair



(No Model.)

M. L. LONG. DENTAL CHAIR.

No. 320,806. Patented June 23, 1885.

UNITED STATES PATENT OFFICE.

M. LUKENS LONG, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 320,8C6, dated June 23, 1885.

Application filed October 20, 1884.

To all whom it may concern:

Be it known that I, M. LUKENS Lose, a citizen of the United States, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Dental Chairs, of which the following is a specification.

My invention consists of a device, described and claimed hereinafter, for permitting the back or other part of a chair to be tilted backward and forward and adjusted laterally, and for securing the said part after adjustment.

In the accompanying drawings, Figure 1 is a rear perspective view of part of a dental or barbers chair with my improvement; Figs. 2 and 3, sectional plans on the line 1 2 drawn to an enlarged scale, and showing the clamping device with the cam-levers in different positions; and Fig. 4, a vertical section on the line 3 i, Fig. 2.

A represents the seat, B the back, and D one of the arms, of a dental chair.

The rod b of the yoke E has its bearings in projections a a at the rear of the seat, pins f passing through the yoke and through holes in the said projections, there being a number of holes in the latter, so that the yoke may be adj usted to diitcrent inclinations. This feature, however, forms no part of my invention.

To the rear of the back B of the chair is secured a guide-bar, G, in the undercut groove of which is a disk, H, and from the latter proj ect the two arms h h, one being above and the other below the upper portion of the yoke E, to which are secured the two collars z i, one collar on one side and the other on the opposite side of the two arms h h.

To the arms h h is pivoted the lever I, and to the forked end of the latter is pivoted the cam-lever J, the opposite end of the said lever I being preferably furnished with a set screw, m.

When the several parts above described are in the position shown in Fig. 2, the back B will be firmlyheld in place, for the two collars t i of the yoke will be gripped by and between the set-screw and cam-lever on one side of the yoke and the guide-bar G on the opposite side; but when the cam-lever has been moved to the position shown in Fig. 3 the collars will be released from the gripping mechanism and the back B of the chair will beat liberty to be (No model.)

tilted backward and forward or turned laterally to any desired inclination.

The collars may be dispensed with, and the upper portion ot the yoke may be gripped by the devices described; but I prefer to use the collars, especially as they serve, in connection with the yoke, to maintain the back B in a central position on the chair.

\Vhile the one arm of the lever I may bear directly against the collar i, I prefer to use the set-screw m, as it permits the ready adj ustment of the gripping mechanism.

The gripping device is shown as combined with the back of the chair, but may be used with other parts of the same-the head-rest, for instance; hence in the claims Ihave specified the parts forming the attachment without regard to the particular portions of the chair to which they are applied.

I claim as my invention 1. The combination of the yoke E, the undercut bar G, the disk H, fitted to said bar lever Lhun g to said arms,aud the canrlever J,

pivoted to said lever I, as set forth.

3. The combination of the yoke E, the undercut bar G, the disk H, fitted thereto and having projecting arms, the lever I, hung to said arms, the set-screw m. carried by one arm of the lever, and the cam-lever J, carried by the other arm of the same as set forth.

4. The combination of the yoke E, having collars i i, the undercut guide-bar, the disk H, fitted thereto and having arms h h arranged between the said collars, the lever I, hung to said arms, and the cam-lever J ,pivoted to the lever I, substantially as specified.

In testimony whereo't'lhave signed my name to this specification in the presence of two sub scri hing witnesses.

M. LUKENS LONG.

\Vitnesses:

JOHN M. CLAYTON, HARRY SMITH. 

